Here’s a potential reason the smallest thing is enough to send you over the edge:
The PTSD cup
A lot of folks, when they enter treatment, will start monitoring their SUDS (Subjective Units of Distress) in some way. That’s, basically, checking in with yourself throughout the day and asking “how full is my stress cup right now?”
Your stress cup (or SUDS, depending on what’s easier) overflows, or hits 10 out of 10 when you get angry and start throwing stuff. Despite how it feels in that moment, there is build up to that.
So, how high are my SUDS when I wake up in the morning (for me, 2 out of 10 - I’m awake, and about as relaxed as I get). I hit about 5 by the time I get to work, with little things bumping that number up or down throughout the day.
Practicing awareness and self-monitoring of that mean you begin to the get the heads up, in advance, “I need to do something to bring my SUDS down/empty my stress cup a bit, because I’m only a irritating computer glitch away from throwing shit”.
Loads of things help de-stress, and vary from one person to the next:)